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STAR Cooperative Agreement R832741: Developing Rapid Assessment Tools to Evaluate the Biological Effects of Complex and Biologically Active Chemical Mixture
Project Purpose:
The overall aim of this study is to test the hypothesis that mixtures of estrogenic chemicals will have adverse effects on the reproductive health of exposed aquatic organisms that cannot solely be accounted for by the summation of individual effects. The proposed study will allow us to survey relevant exposure concentrations for mixtures of endocrine disrupting chemicals that include alkylphenol polyethoxylates, estrogens, and pharmaceuticals in municipal waste water treatment plant effluents; correlate reproductive effects in exposed organisms to biochemical pathway endpoints; and validate the applicability of these biochemical endpoints as rapid assessment tools in field exposures at the surveyed treatment plants.
Project Description(s):
The objective of this proposal is to develop applicable rapid assessment tools to determine biologically relevant effects of exposure to mixtures of endocrine disrupting chemicals. A three-phase approach is employed to complete this objective: (1) we will survey concentrations of relevant chemicals in the effluents of two wastewater treatment plant effluents; (2) in a series of experiments, we will expose aquatic organisms to relevant concentrations of these mixtures, determine their effect on multiple reproductive endpoints, and correlate these effects with alterations in biochemical pathways; finally (3) we will test the applicability of the biochemical pathway endpoints in two field exposure studies using wastewater effluents from the same treatment plants that were sampled in phase 1.
Project Outcomes:
1) The study will determine whether synergist interactions increase the potency of endocrine disrupting chemicals in mixture as has been suggested in recent studies. (2) Provide improved risk assessment by providing a broad range of reproductive endpoints for mixture exposed aquatic organisms. (3) Provide biochemical endpoints that can serve as rapid assessment tools to help regulators determine potential reproductive health consequences for exposed aquatic organisms.
Contact
Susan Laessig at laessig.susan@epa.gov